Bacterial biofilms develop in variety of bodily cavities, including those of the ear, such as the middle ear, and of the nose, such as the frontal or maxillary sinuses, for example. Regardless, the bacteria that generate biofilms often (but not necessarily) are a result of inflammatory insult to tissues, including inflammation arising due to fungi, temperature and pressure changes, allergens, or other sources. The emergence of bacterial growth and associated symptoms is often a cyclical, escalating process with initiation of the inflammatory process facilitating increased bacterial production, which, in turn, causes more inflammation, and so forth. Once bacterial growth has been established, the bacteria will often aggregate, stop dividing, and begin forming protective bacterial biofilm layers, or “slime layers,” comprised of polysaccharide matrices.
The protective bacterial biofilm interferes with the body's natural immune response as well as traditional methods of treatment, often times resulting in chronic, recurrent infections and associated symptoms. In particular, the bacteria emit exotoxins, which incite the body's immune system to respond with white cells. However, the bacterial biofilm interferes with the efficacy of the white cells' ability to attack the bacteria. The biofilm can also act as a barrier against topical administration of antibiotics and other medicaments. Biofilm-forming bacteria also present obstacles to traditional, antibiotic treatments that act to kill dividing bacteria. In particular, the bacteria in a biofilm-forming state may have already ceased cell division, rendering such antibiotics largely ineffective.
For example, relative to chronic rhinosinusitis and other similar ailments, bacteria in the nose can be viewed as a continuum. Some bacterias (e.g., certain strains of pseudomonas and staph aureus) form robust biofilms. Others (e.g., h. flu) form relatively mild biofilms. The biofilms may or may not include or contain fungi. Each of these microbes has a somewhat different or complimentary inflammatory pathway and interacts with the host's immune system differently. For example, staph aureus produces a lipopolysaccharide matrix that acts as an antigen and causes a host response, as well as toxins (e.g., staph exotin A and B, toxic shock syndrome toxin 1 and 2) that can produce an antigenic and even hyperantigenic (hyperinflammatory) response. Other microbes can also produce inflammatory-inciting toxins.
Functional endoscopic sinus surgery (FESS) is a minimally invasive surgical procedure used to treat sinusitis, an infection of the sinuses. FESS opens up sinus air cells and sinus ostia (openings) with an endoscope. The use of FESS as a sinus surgical method has now become widely accepted. For reference, the term “functional” is meant to distinguish this type of endoscopic surgery from non-endoscopic, more conventional sinus surgery procedures.
The purpose of FESS is typically to restore normal drainage of the sinuses, which requires ventilation through the ostia. In particular, a muco-ciliary transport process maintains a constant flow of mucus out of the sinuses with the hair-like cilia of a ciliated epithelium layer acting to direct the flow of mucus toward the ostia. Where there is insufficient ventilation or mucous transportation, infection and inflammation can result, a condition known as sinusitis. Sinusitis often develops from an infection where the maxillary and frontal sinuses meet near the nose or, occasionally, from a dental infection. Regardless, sinusitis causes the cilia to work less efficiently and causes the mucous membranes of the sinuses to become engorged, resulting in obstruction of the ostia. The ensuing lack of ventilation and drainage produce conditions which are ripe for bacterial infection, including biofilm-forming bacteria. As described above, such bacterial biofilms often interfere with effective treatment of bacterial infections, such as chronic rhinosinusitis.
With the foregoing background, it has been postulated that effective treatment of recurrent, chronic inflammatory diseases, such as sinusitis, including chronic rhinosinusitis, requires therapies addressing associated bacterial infections and bacterial biofilms.